1. Field of the Invention
The present invention relates to an electronic control unit and a waterproof case. In particular, it relates to an electronic control unit and a waterproof case, the electronic control unit having a printed-circuit board housed in the waterproof case provided with a respiratory filter.
2. Background Art
As a vehicle-mounted electronic control unit mounted at a site that can be splashed with water in an engine room or the like, an electronic control unit having a printed-circuit board housed in a waterproof case to which a respiratory filter for allowing air to flow into and out of the waterproof case is attached is known (Patent Documents 1 and 2, for example).
In order to prevent a pressure jet from coming into direct contact with the respiratory filter during high-pressure cleaning of an engine room or the like, in one known example, a device is provided with a waterproof case in which a concave portion is formed. By disposing the respiratory filter in the concave portion, the portion at which the respiratory filter is arranged is surrounded by the inner wall of the concave portion, and a drainage channel extending from the concave portion to a side surface of the waterproof case is provided (Patent Document 3, for example).
Patent Document 1: JP Unexamined Patent Publication No. 2005-150376 A
Patent Document 2: JP Unexamined Patent Publication No. 2005-129861 A
Patent Document 3: JP Unexamined Patent Publication No. 2002-134939 A